Lining for rotary pulverizers



ot. s, 1926. 1,601,956

J. R. GAMMETER Y LINING FOR ROTARY PULVEHIZERS Filed Sept. 20, 1924 Patented Oct. 5, 1926.

UNITED STATES PATENT OFFICE.

JOHN R. GAMMETER, 0F AKRON, OHIO, ASSIGNOR TO THE B. F. GOODRICH COMPANY,

OF NEW YORK, N. Y., A CORPORATION 0F NEW YORK.

LINING FOR ROTARY PULVERIZERS.

Application led September 20, 1924. Serial No. 738,815.

rThis invention relates izers of the class known as to rotary pulverball mills,

such a pulverizer normally consisting of a rotary, drum containing the' form of steel balls, rods,

of Hint, or like material.

Alprimary object of cylindrical or conical receptacle or loose grinding elements in hard pebbles my invention is to provide a continuous resilient lining for the drum of a pulverizer ofthe character indicated which can be readily installed and removed, and means for attaching the lining to the drum which are not exposed to the grindin wear o the loose contents.

A further obJect is to provide a continuous, elastic, comp-ressible, sectional lining for a pulverizer drum which shall and attached thereto as be so constructed to maintain the wearing surface portions 'of the lining under compression.

Another object is .to

material is more resistant to wear than har dened steel and other metal liners commonly in use, and has la higher coefiicient of friction resulting in a greater elevation and drop of the contents carried up on the intcrior of the rotating drum. invention is an improvement ber-lined mill and consists'in providing a y d cylinder-contacting surfaces flat, so that the continuous elastic wearing of sections of suitable,

material, and in providing for attaching the sections drum.

In the accompanying drawings, Fig. 1 is a perspective view of a cylindrical, rotary one Aembodiment o being broken away to pulverizer illustrating my invention, partsy The present on such-a rubsurface compose resilient compressible improved means to the pulverizer show the arrangement of the resilient lining sections within the cylinder; Fig. 2 is a transeverse sectional View v tions of the resilient of 'one of the seclining of Fig. 1; and

Fig. 3 is -a similar'cross-sectional view of a modified form of lining section.V

Referring more particularly to the drawings, a. shell or cylinder drivingfgear `11 `and or end closures arbors 13. A door 14 is I show a rotary pulverizer including 10, encompassed by a provided with heads@ 12 in which are secured the also provided for introducing into the cylinder the material to be ground and the grinding elements, and for removin the ground material.

The cylin er 10 is provided with a resillent. lining which is preferably made up of sections 15 in the form of slabs of suitable elastic compressible material positioned circumferentially on the interior surface of the cylinder 10 and secured thereto by bolts 16 extending through the wall of the cylinder. Each section 15 of the lining has a longitudinally disposed, flanged metal channel 17 molded into its structure and adapted tofbe, engaged by the heads 18 of the bolts 16..y The channel 17 may have a plate 19 riveted or welded to its innermost side and extending beyond the sides of the channel` to V'form laterally projecting wings 20. The wings 20 serve to securely anchor the channel 17 in the rubber slab and may be perforated as shown at 21 so as to be more firmly held by the material of the section.`

As shown, the sections 15 are thicker over the channels 17 to provide a substantially uniform thickness of free resilient" material atthe inner or wearing surface thereof. These thickened portions further provide a gently sinuate inner surface for the resilient lining,'a conformation which minimizes excessive abrasion of the resilient material of thJ sections at the portions above the channe s.

It is further desirable that the sections should be molded and vulcanized with their portions on each side of the channel 17 shall undergo a cylindrical deformation upon being secured in place and resiliently press against the inner surface of the cylinder.

The sections 'may be' of such length that one will extend the length of the cylinder,

f or they may be formed in shorter lengths.

In width the sections are such that several are required to cover a circumferential zone, their total width being somewhat greater than the inner periphery of the cylinder 10, so that each section when in place will be l under a considerable circumferential compression, and for this reason more highly resistant to abrasive wear. J

In installing the lining, the bolts 16, are loosely placed in apertures arranged in rows along elements of the cylinder, the rows being equally spaced circumferentially and as many in number as the number of the seclateral edges of the section. Faclng tions. A section 15 is now slipped into the cylinder, the heads of a row of bolts riding in the'v channel 17. If short sections are used, a suiiicient number are employed to extend 'the length of the cylinder. Similar-1 ly, other sections 1.5 are slipped in place over the bolt heads 18 until the inner surface of the cylinder is completely covered, care being taken where short lengths are used to offset the circumferential seams. The sections are then forced to place in abutting relation and the nuts 22 of the bolts 16 set, drawing the channels 17 in closeJ contact 'with the cylinder 10, and holding the sections 15 firmly in place. l

The sections 15 may be composed entirely of a high-grade wear-resisting compresslble rubber stock, such as a pneumatic tire tread stock, or, as shown in Fig. 2,. the sections 15 may be formed of a facing )or wearing surface portion 23 of wear-resisting rubber stock and a backing portion 24 of semi-hard rubber stock having a considerable degree of stiffness but still somewhat elastic and sufficiently compressible to be installed in place under circumferential compression in the manner above described.

Where a section 15 of combination stock is employed, the semi-hard rubber stock of the backmgy ortion of the sectionl 1s prefer-- ably. disposed tocover the plate 19 and to surround the channel 1-7, for the reason that stock of this character adheres more firmly t"o metal than .does -the more resilient and softer stock of the wearing surface portions 23.. The stock of the backing portion preferably diminishes in thickness toward thl" stoc of substantially uniform thickness 1s disposed upon the rstock of the backing/portion and the entire section, including the channel '17, plate 19, backing stock 24 and facing stock 23, is placed in a mold and vulcanizued under heat and pressure.

Sections constructed of the two stocks just described have certain advantages. Thus,

the sections are rmer and stronger land at the same time the wearing surface has all Ithe advantages of softness, resiliency and high resistance to abrasion. The stiffer backing Vstock presses more firmly against the cylinder shell, insuring that` the lateral edges will not leave the inner cylinder surface under severe service conditions, and also adheres more firmly to the anchoring members. 17 and 19 than does softer and nore resilient stock. The backing stock is a less expensive stock than the facing stock and thus a certain .economy in the manufacture ofv such sections results. In the modification shown in Fig. 3, `the sections 25 are formed with an undercut trailin edge 2,6 adapted to overlie the lead ing e ge 27 of the adjacent section. The

channel 17 is preferably disposed nearer the trailing edge 26 in order to insure a tight ship-lap seam between contiguous sections. In other respects, the sections 25 are similar to the sections 1'5 of Figs. 1 and/2, and are applied to the cylinder inthe same manner.

fective or worn sections. The attaching means for the sections are strong and sturdy, as they need be for the severe service to which linings of ore mills are subjected, and

are not exposed to the abrasive effects of the cylinder contents, but are spaced from the inner surface of the sections to give a substantially uniform thickness to the resilient, wearing portions thereof.y The wearing surface of the lining is gently'sinuate to assist in elevating the grinding elements and the material to be ground to higher levels, and at the same time presents novabrupt projections which quickly wear down. The sections are compressed into position on thecylinder not` only to close 'effectively the seamsv between the sections but also to place the rubber of' the sections under a circumferential compression, a condition in which its wear-resisting properties are greatly increased.

While I have shown two forms of resilient lining embodying my invention, lit is obvious that other variations and modifications in the construction of the continuous resilient lining may b e made without departing from the principles of this invention, and that the resilient lining herein disclosedis adapted forv use in other machines than the rotary pulverizers referred to in the specification. I therefore do not purpose-'to limit the claims of this application otherwise than necessitated by the rior art. While a cylindrical drum is here il ustrated, the invention also applies, with obvious adaptation in the shape of the .liner sections, to mills of conical form.

I claim:

1. In a rotary pulverizer, in combination,

a shell, a lining of resilient flexible material for said shell, and a rigid means embedded in the material of the lining and not exposed to the contents of the shell fo attaching the lining to the shell.

2. In a rotary pulverizer, in combination, a shell, a lining of resilient material for said shell, a plurality of longitudinally extending channels embedded in the lining and space d from its wearing surface, and means securing the channels to the shell.

l 3. In a rotary pulverizer, in combination,

the axis of the shell.

5. In a rotary pulverizer, the combination with a rigid shell, of alining therefor having a continuous] elastic wearing -surface l A under circumferential compression.l

6. In a rotary pulverizer, in combination, a shell, and a lining for said shell comprising sections of resilient material, said sections being of such oversize for the shell that when secured in place .a ainst the shell the resilient material of tie sections is placed under compression.

7. In a rotary pulverlzer, the combination,

with a rigidshell, of a lining therefor hav-v ing a continuous elastic Wearing surface under circumferential compression, said linl ing comprising a plurality of longitudinal sections of elastic compressible material, the

combined Width of the several sections being normally reater than the inner periphery of the siell, and means for securing said sections to the shell in compressive lateral contact, whereby the wearing surface -of the lining is held under circumferential compression.

8. In a rotary pulverizer, the combination, With a rigid shell, of a lining therefor having a continuous elastic Wearing surface, said lining comprising a plurality of longitudinal sections of-elastic, compressible vulcanized rubber, the sections being molded With the shell-contacting faces flat, and means for holding central portions of the flat-formed faces in contact with the shell, whereby the marginal portions of the sections are held tightly against the shell by reasonof the cylindrical deformation of4 the sections. v

9. In a rotary pulverizer, the combination, with a rigid shell, of'a li ing therefor having a continuous elastic swearing surface, said lining comprising aplurality of longitudinal sections of elastic material, each section having embedded in the shell-contacting side thereof an internally-anged channel membei' "and rows of bolts aligned on elements of the shell and having heads for occupying `the channel members for clamp- -ing ,said sections lvupon the shell, the sections being adapted to be slipped longitudinally into the shell With' the heads of the bolts riding in the flanged channel members.

10. In a rotary pulverizer, the combination, With a rigid shell, of a lining therefor having a continuous, elastic, highly-resilient .Wearing face portion .and a less-resilient, stiffer backing portion, said face and backing portions being integrally united to each other, and metallic members embedded in the backin to the shelI 11. In a rotary pulverizer, the combination, with a rigid shell, of a lining therefor having a continuous, elastic, Wearing surface, said lining consisting of a plurality of sections, each section comprising a highlyresilient 'rubber face portion and a lessresilient, stiffer rubber backing portion, said face and backing portions being integrally united to each other by vulcanization, and

an attachin member of rigid material em tiguous to its outer face and extending longitudinally of the section.

14. In a sectional, resilient flexible rubber lining for pulverizer shells, a removable section havingfa rigid channel memberembedded therein at its outer surface, the inner 'face of the section being sinuate to provide a thickness of rubber over the channel member substantially equal to that at the edges ofthe section.

15. In a sectional lining for pulverizer shells, a removable section comprising a highly-resilient rubber face portion and a less-resilient stiffer rubber backin portion, said face and backing portions eing integrally united to each other by vulcanization, and achannel member of rigid material embedded in the material of the backin portion for attaching the section to the shell of the pulverizer.

A In Witness whereof I have hereunto set my hand this 18th day of September, 1924.

' J OI-INv R. GAMMETER.

portion-for securing the lining 

